My factory air car has been converted to r134a but sat for a long time without being used and needs to be recharged (I'm assuming). A/C working before sitting idle, now compressor does not come on and cannot see anything in Rec/dryer sight. Has anybody used the trigger cans that hook up to the low pressure side that they have out now?? Or should I just have the dealer charge it?
A/C recharge
mmurphy77
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My factory air car has been converted to r134a but sat for a long time without being used and needs to be recharged (I'm assuming). A/C working before sitting idle, now compressor does not come on and cannot see anything in Rec/dryer sight. Has anybody used the trigger cans that hook up to the low pressure side that they have out now?? Or should I just have the dealer charge it?
I have recharged a system with the cans before. It can be tricky to tell how much you have added to the system and over charging can be a problem. I would take it to a dealer and have the system evacuated to remove moisture from the system. and also have them install a leak detection die to find any large leaks.
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Hey Mike , I agree with Chad especially if it has been sitting awhile.
don't think the cans will do you justice .If you want to bring it to
Goldsboro we have an excellent A/C mechanic here at the shop.
don't think the cans will do you justice .If you want to bring it to
Goldsboro we have an excellent A/C mechanic here at the shop.
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:thumbsup: BTW ,You still going to Miami Subs this weekend ?(weather permitting)
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Dean,
When a R12 system is converted to R134 you need to decrease the weigh in charge by 20%
Bill
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Wouldn't the compressor not coming on be an indication of something more than just a recharge needing to be done?
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Not necessarily, If the system is out of refrigerant the low pressure switch will open and not allow the compressor clutch to engage
Bill
If it's the 71 in his link, it doesn't have a low pressure cutout. There should be power to the clutch any time the AC is switched on. Many GM cars had a Thermal Fuse in the compressor harness that would blow if the refrigerant charge got too low. It's about the size of a domino with a 3 wire connector and clipped to a bracket near the compressor. Not sure about the 71, but the 72 had an AC relay behind the glove box that was prone to failing after many years.
In looking for the thermal fuse I did not find anything like that however there appears to be a low pressure switch a few inches ahead of the low pressure schrader valve in that pipe (can actually be seen in my engine pic in the showroom link - just foward of the rt hood hinge). So when the system was converted it must have been added. I guess I'll let them evac and recharge and see what happens. Been so busy though haven't had the time.
Ooohhhhh, somebody has eliminated the POA valve. Yep, that's a cycling switch. If the system pressure falls below about 40 psi, the compressor won't run. Have the shop look closely at the compressor shaft seal, they are prone to leak. The OEM type ceramic seal can be replaced with a modern double lip seal (same seal as for the H-6 compressor). They seal better and don't leak oil like the old style.
BTW, the jury is still out on the POA valve eliminator kits. There are some concerns about clutch wear because the A-4 clutch wasn't designed to cycle on and off. No personal experience, just thought I'd bring it up. They do seem like a good idea.
Just FYI on the thermal limiter fuse:
Here's one: http://tinyurl.com/yrb885 although he has the model years wrong. It would be in the compressor wiring harness within a few inches of the compressor. There would be an extra wire going to a switch on the back of the compressor also. They weren't used on all GM cars but were quite common in the late 60s-early 70s.
Here's one: http://tinyurl.com/yrb885 although he has the model years wrong. It would be in the compressor wiring harness within a few inches of the compressor. There would be an extra wire going to a switch on the back of the compressor also. They weren't used on all GM cars but were quite common in the late 60s-early 70s.
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yes, if your converting to R134a, use 80% of the R12 charge.
Nope, I don't see anything like that at all.
Probably didn't have one. I just brought it up because they were pretty common and a lot of folks don't know what they are. There's no visual indication when they are bad.
BTW, here's the part numbers for the newer type compressor shaft seal:ACDelco# 15-30948, GM# 2724954
Good Luck
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